Acoustic threshold closure



March 23 1926. 1,577,542

M. c. ROSENBLATT ACOUSTIC THRESHOLD CLOSURE Filed June 22, 1925 Patented Mar. 23, 1926.

UNITED STATES PATENT OFFICE.

ACOUSTIC THRESHOLD CLOSURE.

'Applicati on fileg June 22, 1925. Serial No. 38,787.

To all whom it may concern:

Be it known that I, MAURICE C. Rosan- BLATT, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Acoustic Threshold Closures, of which the following is a specification.

My invention relates to acoustic threshold closures, pertaining particularly to devices for sound-proofing thresholds of doors.

The sound-proofing of rooms, such as professional oflices, for instance, has been a rather recent development in the building art. As far as known all previous practice has been devoted to acoustically treating walls and ceilings, to the exclusion of the threshold openings, although it is known that even small openings transmit great volumes of sound. Professor Watson, in his Acousticsof'buildings states that his experiments show a resonator reading of 0.93 of sound transmitted through a metal lathe and plaster wall or partition, and that after the insertion in the wall of a carefully fitted wooden door leaving, however. a threshold opening o'f-three-sixteenths of an inch, a reading of 7.3 was obtained, and with a threshold opening of one-half inch a reading of 11.7 was had; showing that from an acoustic standpoint threshold openings areof great importance and must be given conslderation.

It is an object of invention therefor to I provide a device for closing threshold open- It is a further object of my invention to provide such a device as a unit that may be applied to doors already installed and which may be easily adapted to varying width doors.

It is a still further object of-my inven tion to provide a pivoted closure carried by the door and operated by the normal and conventional stops thereo Further objects and advantages will become apparent upon further perusal of the specification.

= In carrying out my invention, I provide in its preferred form, a hinged, pad bearing,

strip, adapted to be hingedly mounted near the base of a door, at the outer end of the strip I provide a thin metal piece or element adapted to engage the conventional stop of such door to force the strip to turn on its pivot so that the bearing pad is pushed against the floor to close the opening, and I further provide at the inner edge of the door in the threshold opening a button or similar means to impart an upward movement to the strip in order to clear obstructions, such as rugs, when the door is opened; I further provide means for maintaining the strip in an elevated position such as making the hinges resistant to movement.

In the accompanying drawings:

Fig. 1 is a perspective view of a portion of a door and its associated wall sections, with the device just being raised by the button beneath the door, and with the door slightly ajar,

Fig. 2 is a vertical section through a portion of a door with the device in 1ts downward position closing the threshold opening,

Fig. 3 is a side elevation of a portion of the door with the device just about clearing the button,

Fig. 4= is a front elevation, broken away i and partially in section showing the thin ngetal piece on the strip engaging the door 8 P,

Fig. 5 is a perspective view 'of the metal piece, showing the slots for adjustable mounting on the strip, and Fig. 6 1s a modified form of hinge mount mg.

The door 10,- is spaced from the floor 11, by a threshold opening 13, through which sounds normally may pass. The jams 14, of the door are provided with door stops, as 15, to limit the inward movement of'the door. The door is set in a sound-proof Wall 16.

The device, the subject of this invention, comprises a strip of molding 17, of such weight astoprevent bowing or bending, but yet of such lightness as easily to be handled and operated in the normal movement ofthe door. The strip is rabbeted to form a l0ngitudinal slot 18, in which a cushion 19 is fasgroove. The cushion is a sound-deadening element, and is adapted to be squashed orpressed against the floor.

The upper, inner surface of the strip is channeled to receive one half of the hinges 22, which are held in a desired position in any preferred manner, as by screws 23. The door-abutting portion of the strip is preferably provided with a layer of felt 24, to prevent the passage of sound through the threshold opening from behind the strip.

The hinges may be fastened to the door in any desired manner, so that the strip is pivotally mounted thereon, the ends of the strip being arranged so that they just clear the jams and door stops without contacting therewith. In accordance with my invention I prefer to make the hinges more or less resistant to movement, so that the strip will stay in any position to which it may be moved. This maybe done in a number of ways, but I prefer to cause the upper edge of the molding strip to impinge agalnst the barrels of the hinge, its frictional engagement tending to hold the hinge where set, as will be readily understood. This effect may be enhanced by the insertion of a small strip of rubber, (not shown).

On the inner face of the strip toward the bottom thereof, I provide a small metal piece 25. having slots 26 through which screws 27 pass to provide an adjustable mounting for the metal strip or p ece. Th s piece projects laterally of the strlp 1n position to impinge the normal or conventional stops of the door, to swing the strip about its pivot, to force the cushion against the. floor, as the door is closed. This metallic piece is preferably quite thin so as not to distort the molding strip.

It will be understood that with the strip raised to the position shown in Figure 1, as the door, carrying the strip, is closed, the laterally projecting metallic strip impinges or abuts the stop 15. Continued movement of the door causes the strip to be turned about its pivot, downwardly, to close the-threshold opening 13.

Themeans effecting the raising of the strip consists in a small button or other stop 28, preferably fastened to the'floor, as by means of a screw 29. This is placed in the threshold opening, toward the inner edge of the door, that is toward the hinged side of the door, with one edge on a line with the front face or edge of the door. Thearrangement is such that when the strip is in its downward or closed position, it is just clearing the button, so that the slightest opening movement of the door, carrying the strip, causes the lower edge of the strip to engage the button and to ride over it as the opening movement continues. Thus as the door opens to such an extent that the strip passes over and beyond the button, due to the resistance of the hinges, or some other desired means, the strip is maintained in a raised position, so as to clear all rugs or other floor coverings. As the door is closed, the strip slides over the top of the button until the metal piece engages the stop deflecting it, the strip, to its downward, closed position.

I have found it quite a simple matter to fit this device to varying widths of doors, by providing a molding strip with its associated cushion element, of a width or length as great as the maximum width of door to be treated. It is then quite easy to cut the strip to the required length according to the width of the door under consideration.

' In order to facilitate the attaching of the device to a door, or in the case of a metallic door in which it would be diflicult to drive screws or similar fastening means, I provide the hinge construction disclosed in Fig. 6. This comprises a thin metallic stirrup 30, generally U-shaped to embrace and resiliently engage the bottom edge of a door, and terminating at one side in the barrels 31 of a hinge, which receives the pintle 32, also engaging the barrels 33 of a hinge leaf 34. It will be understood that the hinge leaf 34 engages a molding strip as in the other views. This stirrup has a resiliently gripping action, easily attachable laterally of the door, that is slidable from the open edge thereof, without removing the door, and which is held in position additionally by the upward urge of the strip when it is swung against the floor.

It will be seen that I have provided a simple acoustic threshold closure of eflicient action and cheap construction.

I claim as my invention:

1. An acoustic threshhold closure, comprising a strip, a cushion carried by the strip, means carried by the strip for hingedly connecting the strip to a door, and a thin laterally projecting stop mounted on the strip and extending substantially in line with the rear face thereof in position to engage a stop on such door frame.

2. An acoustic threshold closure, comprising a strip having a bottom groove, an inner face of which strip has a longitudinal hinge receiving depression. a'sound deadening cushion mounted in the groove, and a supplemental cushion strip mounted on the inner face below said depression adapted to bear against a door for preventing the passage of sound between the strip and the door.

3. The combination with a door, and a door frame having stops, with an acoustic threshold closure strip, means for pivotally mounting the'strip on said door, means projecting laterally from the strip toward the rear face thereof adapted to engage one of way to limit the movement of the door,

said door having a threshold opening below it, with an acoustic threshold closure, comprising a strip, a cushion on the bottom of said strip, means for pivotally connecting the strip to the door, said means alsoadapted to maintain the strip in a desired position relative to the door, means carried by.

the strip adapted to engage the normal stop on said doorway to force the stri downwardly to close the threshold opening, and additional means for raising the strip upon f the o ning of the door.

5. threshold closure adapted for 8.850-

ciation with a door, a doorway having sto s. and having a threshold opening below t e door, comprisin a cushioned strip, movement resistant pivotal means carried by the strip adapted to be mounted on the door, means loeatable in the threshold opening in the path of movement of saidstrip during some portion of the opening. movement of said door, to swing the strip against the resistan'ce of the pivotal means so that strip clears and leaves the said means during the remainder of theIope ning movement of the door, and through its closing movement so that-the strip will remain elevated so as 'stops for limitin again to clear the said means as the door is closed, and a relatively thin projecting element extending from the'rear edge of the strip in position to engage the stop of the doorway, and to swing the strip downwardly against the resistance of the ivotal means as it clears the threshold ocated means and the door closes.

6. The combination with a door, with the movement of said door, of an acoustic threshold closure strip, cushions mounted on said strip for deadei. ing sound, a resilient stirrup engaging said door, a hinge leaf pivotally carried by said stirrup and engaging the strip, a laterally projecting element cam'ied by-the strip in position to engage said stop, to swing the strip downwardly on itshinge to close the threshold opening to revent transmission of sounds, and means in the path of m0ve ment ofsaidj stri for swin 'ng the strip vertically on its hinge as the oor is opened.

7. The combination with a door, of stops for said door, of a strip, movement resistant hinges connecting the strip to the door,

means on the strip engageable with the normal stop of the door forcing the strip to turn downwardly on its hinges, and a button under the door in a position to force thestrip to turn upwardly on'its hinges, said resistant hinges so arranged. as to maintain the strip on 'the. door in a desired until positively actuated.

In testimony whereof I afi'ix my signature. 1

MAURICE CJ'RO SENBLAT'f.

sition'. I 7 '0 

